Automatic contouring machine for producing warped surfaces



May 28, 1957 M. MARTELLOTT] ET AL 2, 3

AUTOMATIC CONTOURING MACHINE FOR PRODUCING WARPED SURFACES Filed Sept. 9, 1954 ll Sheets-Sheet 1 IN VEN TOR-'5. MAR/O NA RTELLOTT/ ER WIN 6'. ROEHM y 28, 1957 a M. MARTELLOTTI ET AL 2,7935568 AUTOMATIC CONTOURING MACHINE FOR PRODUCING WARPED SURFACES Filed Sept. 9, 1954 11 Sheets-Sheet 2 INVENTORS.

Z5 MAR/0 MARTELLOTTI f4, ERW/N Q, ROEHM ig- O ZEaz/WYW/ ATTORNEYS.

May 28, 1957 M. MARTELLOTTI ET AL AUTOMATIC CONTOURING MACHINE FOR PRODUCING WARPED SURFACES Filed Sept. 9, 1954 ll Shets-Sheet 3 INVENTORS. MAR/Q MARTEL LO TT/ YER WIN 9. ROE/"IN ATTORNEYS.

y 28, 1957 M. MARTELLOTTI ET AL 2,793,568

AUTOMATIC CONTOURING MACHINE FOR PRODUCING WARPED SURFACES Filed Sept. 9, 1954 ll Sheets-Sheet 4 III/III! INVENTORS. MAR/0 MARTELLOTT/ Y El? WI a. ROEHM A TTURNEYS y 23, 1957 M. MARTELLOTTI ET AL 2,793,568

AUTOMATIC CONTOURING MACHINE FOR PRODUCING WARPED SURFACES Filed Sept. 9, 1954 ll Shee'ts-Sheet 5 ER W/N 63. FIOEHM BY A TTORNE Y8.

y 8, 1957 M. MARTELLOTTI ETAL 2,793,568

AUTOMATIC CONTOURING MACHINE FOR PRODUCING WARPED SURFACES Filed Sept. 9, 1954 ll Sheets-Sheet 6 INVENTORS Mfl R/O N/IRTELLOTT/ BY ERW/N 6 ROEHM ATTORNE Y6.

May 28, 1957 M. MARTELLOTTI ET'AL 2,

AUTOMATIC CONTOURING MACHINE FOR PRODUCING WARPED SURFACES Filed Sept. 9, 19 54 ll Sheets-Sheet 8 l I xy ll 2 /4.3 3 as g I521 J1 IN VEN TORS. MAR/0 Mfl/PTELLOTT/ BY El? W/N G, ROEHM ATTORNEYS.

y 8. 1957 M. MARTELLOTTI ET AL 2,793,568

AUTOMATIC CONTOURING MACHINE FOR PRODUCING WARPED SURFACES Filed Sept. 9, 1954 ll Sheets-Sheet 10 73 I INVENTORS.

' MAR/0 MAHTELLOTT/ ERW/N e. ROEHM 14 TTORNE Y5.

United States Patent ce AUTOMATIC CONTOURING MACHINE FOR PRDDUCING WARPED' SURFACES Mario Marteilotti, Cincinnati,:and Erwin G. Roehm, Norwood, Ohio, .assignors tor'lhmCiitcinnati strun Machine Co., Cincinnati, Ohio, at corporation-of Ohio Application September 9, .1954, Serial No. 454,892

16. Claims. (Cl. 90- -13) This invention relates to improvementszin contour milling machines and hasparticular reference to. animproved form of such machine of the type shown in'UnitedStates Letters Patent 2,674,160.

In the patent aforesaid there has been: shown. in detail a contouring machine in which a first patterncand tracer mechanism automatically controls the .360 degree contouring or profiling movement of the cutter Whileladdia tional -pattern and tracer mechanisms automatically .determine tilting of the cutter axis in two angularly related planes for determination of the varying angular relationship between the final surface produced on a workpiece and the basal supporting plane for the workpiece.-

or the like for airplanes or other parts in which. the final= structure is designed to be produced from a solid block of material or casting into or on which varying contours, recesses, angling rib and face structures, or othercforms are produced by milling or cutting away of the excess material.

A further object of the present invention is the pro vision of an improved control mechanism for the 'angular adjustment of a milling or like cutter spindle in which the desired'angular adjustments maybe made about a selected point on the cutter axis, varying-sizes.of cutters maybe,

utilized, and in which means are provided for'etfecti-ng automatic compensation for tilting adjustment of the cutter irrespective of employment ofcutters of different diameters. In the use of a peripherally .eflectiveamilling cutter for contouring or profiling operations, tilting of.

the cutter for production of warped airfoil, frusto conical, tapered or other workpiece surfaces ordinarily results' 'in a variation in the position of the effective cylinder ofithe cutter in the plane of tilt with respect to the basic tracer determined contour being produced on the'work; In said prior patent certain compensation for such displacement was effected through the use of an automatically oriented cutter supported by the machine for tilting about a fixed point on the cutter edge or surface. i

The present invention has as an object the provision" of improved control mechanism for efiectingproper'and adequate automatic adjustment to produce compensatory movements of the cutter support to correct for such displacement in connection with employmentof a nonoriented cutter.

Another, object of the present invention is the provision of an improved automatic cutter tilt'compensating mechanism particularly effective in those instances in which it is desired that the cutter and its supportingspindlebe 2,793,568 Patented May 28, 1957 tilted about a selected point on the-axisuofrotation "of the cutter spindle.

An additional object of the present invention is the provisionpof control. mechanism effective for accomplishment of a resultant cutter tilt compensation in those in- :stances ":in which. angular adjustment oi the cutter must be simultaneously eifected in more than one planei The present invention further has as an object thtijprovision of an improved depth. control me'chanism'utilizable :eithen individually or in conjunction :with the tilt-compensating mechanism which will serve to maintaina constant ,heightirelationship betweena selected point on the cutter. and the-base or supporting surface for the work being operated upon and will efi'ectively and automatically determine. this depthrelationship during-either simplaor. compound angular adjustments ofthe cutter.

Additionally, the. present invention hasfor itspurpose itheiproyision in connection with. a cutterangle compensating mechanism, actuable .by'the contour controlme'chanism,.:of means to'vary the output rate of drive of the compensator relative to the contouring control input drive, together with means to adjust the effective phase angle. ofc'the' variable .drive with respect-to the contour control input drive.

5 Pi *Otheri objectsxand' advantages of the present invention should be readily'apparent by reference to the following spe.cification,: considered. in conjunction with the accompanyin g drawings forming a part thereof; audit is to be understood that any modifications may be'madein the 39 texact'stmctural details there'shownand describedfwithin the :SCOIXBJOf the .appended claims, without departin'g from or exceedingthe spirit of the invention.

Figure l is an 1 end elevation of an automatic contour- .ingamachinexembodying the principles of the present inwention.

Figure:2 is an enlarged front View partially in -'elevation andripartially insection on the line 2-2 of Figure 1. Figure 3 is a vertical section through-thecontour mechanism control box.

0 Figure:.4 is a sectional view 'at right angles-toFigure 3 onztheline 4-4 of Figure 3.

FigureS is a section on the line 5- 5 bf Figure '3. Figures'o is a detail view of one'of the tilt compensator feedbacksstnrcturesviewed as on theline 6---6-'of Fig- .ureli Figurefl is a vertical section illustrating 'the=valv and bushingzportings in connection with the automatic depth control plunger shown in Figure 3.

Figure 8 is a detail section through'the vertical adjusta mentslidexand related parts.

Figu'rer9 is a fragmentary view of the compensatory mechanism elements of Figure 3 aspositioned forboth contour. anddepth control ofthecutter."

Figure L10 is an enlarged sectional view 'o'f the compensatoryrdrive phase adjusting mechanism;

Figure 11 is a transverse section'on the 'line 11-11 of Figure-10.

, Figure 12 is a corresponding transverse-sectiononthe lme.12'12 of Figure 10.

0s, gure .13 is a fragmentary section on the line13-'--1-3 .of Figure .10.

Figure.,14 is a transverse section on..the l-inc.14-"-'-14 of Eigureil0.

Figure .15 is a diagrammatic view of the-cutter angle control hydraulic circuit.

Figure 16 is a diagrammatic view of the hydraulic actuating. circuit and control valving for. effecting proper accurate positioning of the cutter both radially and axially to compensate for positional variations resulting from tilting movements thereof.

Figure-17 is a plan view of one form of workpiece producibl'bythe present invention."

Figure 18 is a side elevation of such a workpiece.

Figure 19 is a diagrammatic vertical sectional view illustrating the effect of tilting of the cutter in a direction toward the workpiece. I

Figure 20 is a diagrammatic plan view illustrating the effect of the combined tilt of the cutter in a direction toward and a direction substantially tangent to the surface to be produced on a workpiece.

Figure 21 is a diagrammatic plan view illustrating the relationship between the compensator form and follower when the cutter occupies a non-tilted position.

Figure 22 is a similar view illustrating the required ,follower adjustment to compensate for tilting of the cutter.

Figure 23 is a diagrammatic view illustrating the principles involved in obtaining a controlled non-uniform rate of drive for the compensator mechanism.

Figure 24 is a diagrammatic vertical sectional'view illustrating the necessary compensating adjustments when the cutter height is to be maintained constant.

Figure 25 is an orthographic'projection illustratingthe .required adjustment factor for compound tilting of the cutter while maintaining the effective point on the cutting edge at a constant height.

In the drawings, in which similar characters of reference are employed to denote corresponding parts throughout the several views, the numeral 25 (Fig. 1) designates the bed of a machine embodying the present invention having a table or work supporting portion 26 at one .side and at the opposite side the column section 27 supporting the contour determining template 28,. and by way of the adjustable brackets 29 and 3f] the templates 31 and 32 reacting on the tracer fingers 33 and 34 carried by the tracer heads 35 and 36 to determine the angular positionings of cutter-spindle 37 carrying the cutter 38. .Longitudinally movable on the bed 25 is the cutter or ,tool supporting carriage 39 shiftable by pinion 4f) driven by the hydraulic or other motor 41 and meshing with the rack 42 on the bed. Mounted on the carriage 39 for in and out or transverse movement, as viewed in .Figure 1, is the ram 43 shiftable by pinion 44 meshing with rack 45 on the carriage, this pinion being driven by the hydraulic or other motor 46. The motors 41 and 46 are controlled as to their relative rates of operation by the conventional 360 degree type tracer head indicated-at 47 having a tracer finger 425 for engagement with .fhe pattern 28 on the column 27. As is conventional in structures of this character, the exact direction of relative movement of cutter 38 with respect to a workpiece such as 49 indicated on the work supporting table 26, is the resultant of the relative rates of actuation of the motors 41 and 46. Details of one form of known commercial structure for so controlling a pair of motors for performance of 360 degree contouring operations are shown in Letters Patent 2,412,549, and in themselves form no part of the novel features of the present invention.

Inthe present instance, as is shown in Figure of Letters Patent 2,674,160, the rotary drive motor contained in the tracer head 47 for effecting the contouring adjustment of the tracer mechanism serves also to drive an auxiliary power shaft 50, which in the present instance is utilized for control of the compensating mechanism, the shaft thus' being driven and operating in synchronism with the rotational action of the tracer motor to the di- Erection and extent determined by the contour pattern effected deflections of the tracer 48. Mounted on the ram 43 for movement therewith and in limited in and out adjustment with respect thereto, is the horizontal slide 51 whose position relative to the ram is controlled 1 bypiston 52 having a rod 53 coupled to bracket 54 on the slide. This piston is reciprocable within the cylinder '56 on the ram, the parts thus providing a hydraulic motor under control of the compensating mechanism.

Movable across the forward face of the slide 51 is a transverse slide 55, its transverse movement being con- 4 trolled by hydraulic motor of the piston and cylinder type indicated at 57.

Vertically movable on the face of the transverse slide 55 and guided by the ways 58 (Fig. 2) is a slide 59 supporting the hydraulic cylinder 6t (Fig. 8) receiving piston 61 having a piston rod coupled by bracket 62 with the supporting slide 55 for hydraulic control of vertical movement of the slide 59. Such movement is facilitated by the counterweights 62 (Fig. 1) suspended from a flexible chain or cable 63 extending over the pulleys 64 and 65 and connected to the vertical slide 59 at 66. The vertical slide 59 is provided with arcuate ways at 67 (Fig. 2) for the oscillating carriage 63. Motor 69 (Figs. 1 and 8) through gearing 70 and spline shaft 71 journaled in the vertical slide 59 drives pinion 71 meshing with arcuate rack 72 on the oscillating carriage 68 to effect movement of the carriage around the arcuate path established by the ways 67. These ways are preferably concentric with the point 73 (Fig. 2) which lies on the axis 74 of the cutter spindle 37.

The oscillating carriage 68 has an outwardly orforwardly extending bracket portion 75 (Fig. 1), inturn provided with arcuate ways at 76 preferably extending at right angles to the ways 67, supporting the oscillatable spindle carrier 77 having a bearing portion 78 rotatably mounting the cutter spindle 37 andsupporting the drive motor 79 (Fig. 2) for the cutter spindle. An arcuate rack 80 on the spindle carrier 77 meshes with drive pinion 81 connected by shaft 82, and gearing 83 with drive shaft 84 extending into casing 85 (Fig. 1) where it is operatively connected to motor 86 for effecting the forward and back tilting movement of the spindle carrier. -In accordance with the principles of Letters Patent 2,674,- 160, operation of motor 86 is controlled by patterns effected deflections of tracer 34 and motor 69 is controlled by pattern effected deflections of tracer 33 to determine the two angular adjustments of the cutter spindle axes. The hydraulic circuit for this control is shown in Figure 15, including the pressure supply pump 87, pressure conduits 88 extending to the tracer heads 35 and 36, the return conduit system 89 coupling the tracer heads with reservoir 90, and the motor circuit conduits 91 and 92 for motors 69 and 86, respectively. A variable relief valve 93 interposed in the pressureconduit system 83 between the pump and the tracer heads serves to maintain a predetermined pressure in the supply system while by-passing any unused volume back to the supply reser- .voir 90.

To illustrate the manner of utilization of the present invention, there has been shown in Figures 17 and 18 respectively a plan view and view in elevation of one form of workpiece ordinarily very diflicult to manufacture, which can be readily automatically produced by the machine of the'present invention. The workpiece there shown has been machined from a solid block or piece of material and, .to bring out the potentials of the invention, has been indicated as having the circumscribing periph cry 92' of its body portion generated with a warped or conical airfoil surface. The base contour line, indicated at 93, corresponds to the contour of the pattern 28 followed by the 360 degree movement controlling tracer 48. However, the contour 94, at the top of the workpiece differs not only dimensionally as to major and minor axes but is also dificrent in shape or outline from the automatically determined basal contour 93.

For an appreciation of the manner of production of surface 92', there has been indicated at the points 95,

,. are, of course, parallel to the spindle axis 74 and may be considered as indicative of the position of this axis, and the amount of tilt that has been imparted by the combined effects of the angular adjustment of the oscilreases.

of this tilting action hasnbeen indicated in, Figure 2 as 'at the point 73 lying in thecutter spindle 74 and at the base'of the cutter 38. Whernthe edgeof the. cutter is following the pattern contour 93jand the cutter is in untiltedposition the contact betweenthe cutter and work surface will be at the point101 asnshown in FigureZO. The distance from the point 73, which generates the. contour path of the cutter axis in accordancewith the path of movement of the tracen axis tothe point 1 .for engagement of the workpiece by the cutter corresponds to the radius 102. of the cutter cylinder. However, when the cutter is tilted as shown in Figure 19 by oscillating only carrier "77 with theupoint .73 remaining stationary, the effective surface ,of the] .cuttercylinder will move toward the .work an additional amount as indicated at 103. In the absence of some. compensatory adjustment of. the cutter the work would beundersized by the amount of the auxiliary radius 103, It is the compensation for this adjustment which is efiectible by thelimited movement of one of the horizontal slides; in theparticul ar instance shown in Figure l9,the.s1id e 51,

When the tilting adjustment of the cutter for proper surface production demands positioning of its; axis, as

indicated, parallel to. the line 96,. for example, thereis a tilting movement not only inwardly or toward the workpiece as respects the upper. portion .of the cutterbut likewise a tilting movement longitudinally of the surface being produced, the. resultant effect of these two movements. being a shift in the point of contact, Figure-20,

to point 105. For restoration to point 101 of engagement for proper contour reproduction, it isnecessary that suitable adjustments be made by meansqf the slides 51 and .55. Thecompensating movementofslide 5 1 is indicatedby .vector 106 in Figure 20 and the compensating movement effected by slide 55 is indicated by vector1 07 and the resultant compensating. movement by the;vector 108.

The compensation control mechanism is located .within theframe or housing 109; Figures 1, 3, 4, and. 5 carried by. the ram 43. Supported by this housing on the trunnions 110 and 111 is a yoke 112 having two sets of arouate guides 113 and 114,. the said arcuate guides having their centers of curvature lying on the axis. 115 of the trunnions. Yoke 112 i s keyed to the trunnion 111-which is provided with a worm gear 116 meshingtvvithworm 117 on drive shaft 118. Shaft 118 is driven; through he ti s .119, ur 1 hr eter l hi 11Jdtm PF the angular adjustment of the oscillating carriage 68 to eiiect equal and synchronous oscillation or angular tilting of the yoke 112.

Mounted on the arcuate guide 113 and arcuately adlower. end gear .142 meshing with idler 143, which, in

justable along the guide by the shaft and gearing 1 20 (Fig. 3) is the cutter tilt compensating slide 121. The

power shaft of the drive 120 is connected through gearing in box 85 to the motor 86 which also drives the shaft 84...

controlling the tilting of the spindle carrier 78in a transverse plane. The direction and amount of tilting or arcuate movement imparted to the slide 121 will correspond to the amount of tilt of the spindle carrier. Carried'by the slide 121 is a collet or chuck 123 supporting the cornpensatory plug or cutter representation form .124 whose axis 125 intersects the common axis 115 of the trunnions 110 and 111 at point 126 which for operativepurposes.

corresponds to the point 73 about which the cutter is tilted. As a result of the manner of mounting of the compensating plug or form 124 and the drive controlling the positioning of the yoke 112 and slide 121, the form 124 will therefore partake of the various tilting adjustments imparted to the cutter, and in a like manner.

Journaled in the portion 127 of the housing or frame 109 in co-axial relation with the collet 123 and form 124 when they are in a vertical or non-tilted position as indicated in Figure 3 is the: spindle or stub shaft 128 bearing pn its lowerend the drive .gear 122 and having at its 6 ppeh nd-lthefiensec p thwaye 1, F u e 6, IS Ge SZJWhich in tu n s ppo t th t flow J 3 w ch engages the form A spring 134 intervening the flange 130'vand theslide 132, urges the. Slide toward the left as viewed in Figure eccent i 36-, Cchseq n ly e, eccentric, es if eb on the ways 139, willbeshifted in unison with any follower produced movement of slide 132 during rotary. or circhmemb lat ry vem ntc th w r 1 a oun e. or 1 4-; he g ner c memhu e e y o n .cf-the ecce tric is eflie e by e drive to es and137 If both are driven at the same rate the movement he eccentr c, llh e tr c e eth mcv m d rect yimnert iih s ide however, t rei enrich-arise in p a e e t e g rsl 1 h re will he ai shheht cros shi n of e entr c h. t inte rn ediateslide 133 so that the effective contact positioning of theeccentric will be a resultant of these comied. in rements hxheled.. h t e th m p t n .1 i h ralle r ation to the shaft 1281s the drivesleeve 141 having at its turn, drives gear 129 on thesh'aft 128 sothat the shaft n l ve l r a e .i t s me d r c c l bly chht d w hinthe s ev 1. i t e pt c nt ol l eve 44 havin th n e .ebly. eiving r ep i 146ca ried by fiange 147 of sleeve 141. t

In the positionof the parts shown in Figure 3, sleeve 144 is maintained. in an intermediate or neutral position by head 148 of the interlock pin 149 operated by -bell crank 150, (see also Fig. 4) which is, in turn, connected by link 151 to the operating bell crank 152 engaged in a groove in the manually operable phase shifting knob 7153 as shown in Figure 4. Bellcrank 1 50.is carried by shaft 154 having an arm 155 operatingthe interlock pin 156 extending upwardlythrough a bore in the shaft 128. Gear '142 is driven through idler 157, and gear 158 which carries the knob 153 and is slidably mounted ion the shaft 159. Spring pressed idetent 160 .(Fig. ,10) engageable in the grooves 161 of shaft 159 determine the axial'po sitioning of the gear with respect to the shaft.

Thedrive-is from-shaft-SO (Figs. 1 and-3) through a conventional second universal joint and bevel gear drive to shaft 172, gear 171, gear (Fig. 4), drive sleeve 169, the double universal joint mechanism designatedas an entirety by the numeral 177, shaft 159 and gear 158 to the idler gear 157. Gear 157 drivesgear 142 on the sleeve 141(Figh3) and also, through idler 143 and gear 129, drives shaft 128 at the same rate and direction as the direction of drive of sleeve 141. t

In addition, the gear 170 through intermediate compound gears 178 and-178' (Fig. 5) drives gear137 for effecting rotation or rotary angular adjustmentof disc 136, as shown in Fig. 3, at the same rate and direction as the rate and direction of operation of the drive gear 170.

When the compensator elements are in the vertical or non-tilted position, indicated in Figure 13, the drive imparted to the shaft 128'and to the disk 136 by gear 137 I will be equal in direction and amount, b'utwhenthe cutthe reference character 177 and particularly illustrated as to structure and principle in connection with Figures 4, 5,- and 23. Mounted in the bell or housing 180 at the upper end of the drive sleeve 169 on the pivot pins 188 is the yoke 187 of the primary double gimbal bearing universal joint pivoted at the points 186 to the angularly adjustable housing 184 on one end of the swinging control rod 185. The housing 184 is pivoted at 183 to the inner yoke member 182 which is, in turn, pivoted to the pin 181 on the shaft 159 angled 90 degrees from the points 183. 'When the rod 185 is in vertical or untilted position, as viewed in Figure 4, the rate of drive transmitted from sleeve 169 to shaft 159 will be uniform, but when any angular adjustment is made of member 185 the resultant reaction on the double universal joint connection will correspond to the showing of the diagram, Figure 23,as' though the members 159A and 169A were linearly connected by a first universal joint yoke and mechanism 182A and a second universal joint mechanism 187A with an intermediate shaft corresponding to the intermediate element 184A. By this structure a drive is imparted from 159A to 169A or their equivalents 159 to 169 when the member 185 is tilted, at a uniform number of revolutions, but during any individual revolution at a continuously incrementally varying rate of accelerated or decelerated angular adjustment of the driven member 159 as respects the rate of rotation of the driving member 169. In effect, therefore, an automatically adjustable variable speed drive or transmission is interposed between the drive shaft 172 and the final synchronously driven members 128 and 141. In order to effect the transfer of the angular displacement originated by tilting member 185 of the doub le universal joint to the driven members 128 and 141 so that follower 133 will assume a position relative to form 124 in proper relation to the contact of the cutter with the Work, the double joint mechanism must be oriented with respect to the follower 133 and slide 132 so that the axis of pivot 188 is parallel to the motion of slide 132 as shown in Figure 5. This relationship may be modified, as later explained, within any part of a revolution of the shaft 169 as required for purpose of correcting the position of follower 133 and hence the cutter vposition relative to the work. Thefollowing table illustrates the mathematically determined amount of relative angular movement imparted 'by the drive illustrated, to the follower 133 on shaft 128, as respects the rate of movement or rotative adjustment of the gear 137 slidably supporting the eccentric 136.

assess 4) coupled by' link 190 with the slide 121 for movement in synchronism therewith. Pivoted to the slide 189 at 191 is the shifter arm 192. By reference to Figures 3 and 4 it will be evident that oscillation of the yoke 112 will effect through arm 192 a like oscillation of the rod 185, rocking it about the center of the universal joint as indicated by the dotted lines in Figure 4. Correspondingly, the movement of the slide 189 on its arcuate guide 114 will cause a corresponding oscillation in a right angle plane of the rod 185 so that its resultant position will again be in effective and functional correspondence with the resultant angle of tilt which has been imported to the cutter axis.

In the milling of warped surfaces consideration must be given to two major conditions. One of these conditions is illustrated in Figure 20. The cutter, an end mill, is swung in two right angled directions, longitudinal and cross, so as to obtain on the workpiece an element of the surface generated along the direction of the line tangent to the cutter and inclined to a compound angle determined by tilt in two directions.

To generate the desired changing slope on the machined surface, the cutter is continuously adjusted in angularity by reaction of templates 31 and 32 against tracers 33 and 34, which determine the tilt of the cutter in two right angle planes, so-called cross and longitudinal.

The 360 degree tracer does not tilt, but follows the periphery of a flat template of the outline of the contour to be produced on the workpiece. and guides the cutter along this contuor, by operating the main longitudinal and cross slides. The tilting of the cutter at its center introduces modifications on the contour because the horizontal section of the cutter in tilted position is elliptical and its efiective contour is shifted with respect to the desired contour relative to tracer by amounts equal to vectors 107 and 106 as indicated in Figure 20. To restore proper relation between the surface of the cutter and the work for template contour reproduction, the corrections 107 and 106 are obtained by superimposing movements equal to vectors 107 and 106 is the longitudinal and cross directions so as to cause the tangent point 105 of the elliptical section of the cutter to be displaced to point 101 corresponding to the point of tracer contact with the contour pattern 28.

The effective outside elliptical contour of the cutter as respects its point of engagement with the work will be duplicated by the concomitant tilting of the plug or form 124 with respect to the follower 133 as has been structur- Table I 72 Angle of tilt of Universal Joint Shaft 185 Tang. t, Angle degrees t, Deg. 005 1 970 .882 750 587 500 0 10 20 30 40 Angle 4 Degrees 0 0 0 0 0 0 364 20 20 2032 2229 2552 3135 362 839 40 40 4053 4335 487 5 5912 cfeases 1. 732 60 60 6049 632 6638 7120 73 55 5. 6713 80 8010 8110 8228 846' 8458 m 9O 90 90 90 90 5. 6713 100 9942 9850 9732 9556 952 1. 732 120 11915 11658 11325 10840 1068 a de- 839 140 1398 13636 13145 12442 12057 creases 364 160 15924 15732 1546 1487 14356 0 180 180 180 180 18 180 tan t=tan. g. Cos 'n.

g=angle corresponding to angle rotated through by output shaft 159.

N0rE.--These values are repeated in the order given in the 3rd and 4th quadrant.

Automatically to efiect the indicated variations or angular positions of the control rod to correspond with the tilting movement or adjustment of the cutter ;axis, the arcuate guide 114. on the swinging yoke 112 ally indicated in the cross section of form 124 in Figure 5. As there shown, this tilting has had the effect of moving slide 132 to the right. The slide in the position shown will react on eccentric 136, moving same to the :supports the arcuately adjustable slide 189 (Figs. 3 and 75 right. Peripherally engaging member 136 is the head azaaree 9v ,193ofva1ve-194 slidable in valve bushing lfli groove 198 of thebushing 195 while additional grooves 199 and 200 are coupled to the reservoir conduit system 89. The valve structure shown is of the sensitive servotype basically including the central valve spool 201 movable for, determining the existence of a dominant pressure condition in the conduit 202, coupledwith' the left hand end of cylinder 56 to move pistion 52 and thus slide 51to the right, or in the conduit 203 to move the piston to the left, Feed back connections, as hereinafter described, serve to reposition the bushing 195 to limit the movement of the slide.

Disposed at a point 90 degrees from the valve 194 -is a second valve 204 movable in thesliding bushing 205. The'valve and bushing structure are similar to the parts 194-195, the valve 204 correspondingly controlling the pressure conditions in cylinder 57-which react on piston 206 to control the transverse movement of slide 55.- It

will be evident that asthe members 133 and 136 rotate about the axis of the form 124 the amount of radial displacement of the periphery of the eccentrio136 will be controlled in direction and amount by the movement of pin 135 in direct line relation with roller 133 as determinedby-interengagement of the member 133withthe tilted or angularly displaced surface of the member 124. Due to the sine and cosine relationship provided by the slide-138 supporting eccentric 136, the displacements of thetwo valves controlling the movements indicated by'the arrows 106 and 107 in Figure 20 will be such that the resultant positioning of the cutter, as indicated by the vector 108, will be determined automatically by the displacement of the slide 132 and eccentric 136 and the relative sliding and rotational movements of slide 138 and eccentric 136.

From the preceding description of the necessary directional compensating movements indicated in connection with Figure 2.0, it will 'be evident that when the contact point 105 of the cutter is shifted into coincidencevwith the .necessary point 101 for contour reproduction-that this .point is, in effect, angular-ly displaced from its normal vertical relationship at 101 an amount represented, for example, bytheangle 20?, l-'i,' ure,22, For mostaccurate reproduction purposes, it is, thereforenecessary that the p-oint of contact of the member 133 .be-angularly shifted relative to form 124 througha corresponding-angle. It has been discovered that this angular ,displacementis the same as the. angular notational displacement ,of s haft 159 slide 138 and eccentric 136 through pin 135, which-will.

Set q ried t tha oidca ihW fi i Hl P the shifting of valves 194 and 204 to effect a correct positioning of the cutter at the resultant position. The amount of this angular displacement is in accordance with the given double universal joint formula in which the angles are measured relative to the minor axis of, the elliptical section resulting from tilting in the direction as indicated by the line AA in Figure 20. The amount of n u ar p emen i e f r n b w enthe a le measured from the minor axis to the starting position ata h i 1. s active ,a ii er e am mor bf 1 h 10- 01. nr iqfi alrq tiq ta 0 hen the driv from s H .7 15 in direct qn cf he contour-cu p ttern e trace :1 causes rotation of rotaryidrivemotor in head 47. With ucrhangq i the t lt 9 thew e hene t b haf 128 ,is driven through thevariable angle universal joint mechanis h amu et t incremental aser wer with respectto thedrive shaft 172 will vary in accordance with thepreviously given mathematical table and will be the correct necessary amount for advance or retraction of the follower 133 with respect to its arcuatemovement around the form or piug 124n At the same time due to the constant rotative adjustment of gear 137 and ,the variable rate of rotative. adjustmentof theshaft 12S slide 132 due to the interyention of follower 133 will determine a path of movement of pin 135,;.which, wili effect not only a oorrespon-dng a a iu tnlentp e n r c ositio n fifths cc nt 61a a di q t ita al e W t r' ir ti o m vemen of the slide 132 but, due to the cross slide mounting, such angular relative adjustment of the parts will result in an additional 9 0 degree phased lateral displacement of the member 136 in a second radial direction at right angles to the direction ,of movement of the slide 132, The ultimate effective positioning of the periphery of 136 willtherefore be ,in a resultant direction such that the necessary corrective positionings of the two compensation control valves 194 and 204 will accurately variably position the supplemental slides intervening the main ram 43 and the oscillating carriage 6 8.

An additional problem is presented if it is desired to maintain the edge of the cutter at constant height relative to the work aschanges occur in the angle of tilt of cutter The center of swivel or tilt ofthe cutter is at point'73 on the cutter axis. Because of the above condition thehorizontal cross-section of the-cutter, when moved in a plane normal to the base plane of the work to compensate for the elevation change of the cutter edge, resulting from the tilting adjustment of the cutter axis, forms an ellipse which is inside the cutter circle, and corrections in the position of cutter must now be made as indicated in Figure 25 to bring point T of the elliptical section of the cutter into correspondence with the respective point T-l on the tracer which is in contact with the contour determining pattern 28.

The nature of the required adjustment and the reason for same-willbe apparent by reference to diagrammatic view, Figure 24, which indicates angular adjustment of the cutter spindle in a single plane. It will, of course, be understood that the corresponding-condition will 'be effective-in the right angular plane of opposite tilt-ofthe cutter, and that the actual amounts of compensating movement necessary will be a factor of the resultant position of. the cutter spindle axis. In Figure-24 the normal vertical positionof the cutter 38 has been indicated-by: thedash line figure designated by the letter V while the angularly tilted position of adjustment ofthe cutter about its center of swivel 73 has been shown by the full outline T. It will'be noted that by this tilting the edge of the cutter adjacent the work at T-l has moved downward antamount measurable by the line T-2, while theweffective surface of the cutter has rnoved inwardly in thedirection of the work periphery 92' an amount indicated as T-;3 corresponding to the amount. 103 in Figure 19 Whendt is desired, however, to maintain theipoint T-lin the original plane l? or baselineof the worl; it is necessary that the spindle carrier 77 and its supporting oscillating carriage 68 be vertically adjusted by movement of slide. 59 in thedirection of the arrow 208 of Figure 24. Thisadjustment will move the cutter, shifting the point 73 upward to the position 73T and the cutter as an entirety will then occupy the position shown by the dotted lines TVA. By comparison of the dash outline V repretat cs t e t e i w r ir .p on d the dotted outlineTVAi epresenting the cutter in its tilted and vera 11 a 1 vtical adjusted position it will be noted that the point TVA-1 is now remotely located as respects the work surface 92. Therefore, with this combination it will be evident that for proper following of the contour outline at the base of the work, it is necessary that the cutter be adjusted in the direction indicated by the arrow 203 or toward the work in place of the adjustment indicated by the arrow 1116 of Figure 20 in which the cutter had to be given a compensating adjustment in a direction away from the workpiece.

"Figure 25 is an orthographic projection showing in plan view the basic cutter periphery and the inside ellipse efiect of a resultant axial tilt of the cutter about the two angularly related planes of tilt established by the supports for the oscillating slide and spindle carrier, after vertical adjustment of the spindle-to maintain the point T-l on [the cutter edge at a constant height. The diagram further illustrates'the necessary lineal adjustments, vertical F, transverse a and cross b for ultimate correct compen- 1 satory adjustment of the cutter position.

Figure 25 shows further that the elliptical section is now oriented with its major axis at 90 degrees to the direction AA of tilt, instead of the same direction as in case #1. Therefore, we are operating in the second quadrant of the values shown in Table I. This condition requires an angular displacement of channel 212 and finger 211, Figure 9, from a position corresponding to point T1, to a position corresponding to point T to elfect the necessary corrections a and b, which result.-

in bringing point T of tilted cutter to T-1. This correction made with axis of tilt in position AA as in case #1 and the double universal joint oriented as shown in Figure 5 for case #1 would result in rotating finger 21.1 not in the direction to position point T-l at T but to displace it instead in the direction of case #1.

To avoid this condition, the universal joint 177 must now be oriented to a position 90 degrees from the position shown in Figure 5 to effect a 90 degree positional shift in the occurrence of the accelerated and decelerated angular adjustments previously described in connection with the use and functioning of the double universal joint drive 177. Due to properties of the double universal joint, the acceleration and deceleration of shaft 159 will now be interchanged as respects the reaction in the position of case #1 when shaft 185 is tilted in the same direction as incase #1. Because of this shift the correcting mechanism will be now operating in accordance with the values given in Table #1 for the second quadrant.

T 0 effect the change in reaction or orientation of the reaction of the double universal joint 177, use is made of the construction shown in .Figures 4 and 10.

Keyed on the lower end of the shaft 159 is a collar 162 having an upper flange 163, lower flange 164 and intermediate groove 165. The upper flange 163 is provided with a notch 166, Figure 11, to receive the 1 clutch tooth 167 carried by the hub of gear 158, while the lower flange 164 is provided with a similar notch or recess 168 phased 90 degrees from the notch 166 as particularly illustrated in Figure 14.

The clutch tooth 167 has been indicated in Figures and 11 as engaged in the notch 168 from which it may be disengaged by inward or, as viewed in Figure 10, upward movement of the knob 153 to an extent limited by the overhang of the upper flange 163 when it will lie within the groove 165.. With the parts in this position a quarter revolution may be given the knob 153 in a clockwise direction as viewed in Figure 11 when continued upward movement of the knob will partially engage the clutch tooth 167 in notch 166. Reverse actuating movements of the knob 153 will serve to disengage the clutch tooth from notch .166 and reenage it in notch During this movement the gear 143 turns with the knob 153, imparting a 90 degree rotational movement in a clockwise direction to the 12. gear 129 carrying with it the slide 132, but the gears 1'70, 171 remain stationary. When the clutch tooth 167 is partially engaged in the notch 166, the knob 153 may be turned in a reverse or counterclockwise direction and will carry with it the shaft 159 which will cause a degree phase shifting of the universal joint mechanism just described and a restoration of the slide 132 to its previous position, but again without rotation of the gear 171 and thus no change in the phase relationship between the 360 degree tracer control motor and the slide 132. This action will, however, effect the necessary 90 degree change of phase relation between the universal joint drive mechanism and the parts driven by said mechanism, which is necessary when the compensating action is to be with respect to the inside ellipse cutter and work relationship when the cutter is to be maintained with its effective edge at a constant height as distinct from the outside ellipse relationship when the compensation is purely for cutter tilt but Without vertical compensation. The parts having been rerotated as just described, upward movement of the knob 153 is continued to cause an interlocking of the clutch tooth 174 on the gear 170 with the advanced notch 175 in the collar on the double universal drive sleeve 169, the parts then being locked together for driving purposes in this 90 degree phased relationship. This phase shifting cannot be accomplished, however, until interlock arm 152 engaging groove 152' in hub of gear 158 is released by first making the changes indicated in Figure 9.

For effecting automatic compensating positioning of the cutter, use is made of the structure particularly shown in Figure 9. On the chuck 123 is supported for rotary movement the C-shaped bracket 210 having the finger 211 whose tip extends from the axis an amount .Corresponding to the radius of the cutter being employed. The tip engages the surface 212A of the channel 212 of the bracket 213 which is substituted on slide 132 for the follower 133. The bracket 213 has an opening 213A to allow free movement of interlock rod 156. The bracket 213 is carried by and controls the movement of the slide 132 and during rotation carries with it the finger 211 so that there is constant contact between the finger 211 and surface 212A at a distance from the axis 125 representative of the position of the effective portion of the cutter.

At the same time the central ball and stud 214 is removed from the rotary chuck 215 carried by the slide 189 and in its place is mounted the depth control unit which includes the disc 216 carrying the stud 2117 hearing a ball or contact 218, the axis of the stud and ball being radially I displace from the axis of rotation 219 of the chuck 215 the valve 233 to the extent permitted by the interengagcment of the ball 218 and flange 1 .5.

Oppositely, the spring reacts to .urge downwardly the siidably mounted valve bushing 234 to maintain the finger or contact point 235 in engagement with the feed back lever 236.

By reference to Figures 3 and 9, it will be evident that when'the neutralizing interlocks 156 and 143 are released the flange may move upward to ride in cngugemer with the ball 218, drive imparted to flange 1 15 serving through the lugs 231 to carry the ball 2.13 around in an arcuate path but at a variable height from point to point in the path, depending on the double angular tilting imparted to the supporting chuck 215 by movearcades.

ei t: o sp ds to t e a ount of e t ca m vem n necessary to. maintain the -point T-l of the, cutter at a constant height from the bed or base of the machine during varying t angular adjnstmentsnof the cutter and its supporting; spindle;

Upward movement of flange 1451andvalve233, Figure 16, serves to couple pressure conduit 88 with conduit 237 introducing pressure. into the upper end i of cylinder 60, raising vertical, slide 59.; :As the-slide is moved upwardly, rack .238, throughpinion 239 rotates the feed b'ackshaft 240, driving pinion 241 which actuates feed backgslide 242, rocking lever r236. .iaboutthe adjustably supported fiulcrumtmember 243,, The opposite end of the lever. reacts against the end of the finger 2,35, elfect ing feedback of the servorbushing 234 to limit the amount of vertical cutter support adjustments It will be understooddhatdownward;movement or depression of the flange 145 below its normal neutral position will introduce pressure into conduit 244 extending to the lower end, of cylinder 60, causing corresponding downward movement of the gutter support.

The accuracy of the corrections ;made by the comp ns t n ;meehan pe d 1 onthe location of the pointeror follower 133 with respeeeto the cylinder or forrn 124 Figure 3, in theone case, or the position of; finger 211 and guide channel 212, Figure 9, in the second case. i The tilting of the cutter-at any compound angle changes-its point of contact with the workpiece as respects the, contact determined by the 360 degree tracer ,withathe pattern 28. Assuming case one, when cutter is tilted in the resultantdirectionas indicated by line A--A, Figure 20, with respect to main axes XX and YY of the machine, thecontour C of .cuttert section becomes an ellipse (B), the-major axis a of which is equal to the cutter radius 102divided by cos n where n is the angle oftilt of cutter: axis around point 73 in the plane AA. The minor axis, b, is equal to the cutter radius 102.

If, after tilting, no change were made in cutter position, the contour milled would be D, and the cutter would contact the workpiece at point res, an amount 107 away fromcorresponding point 101 of tracer, and an amount ltldinside; desired contour line B.

In orderwto correct the position of ,the cutter so as to maintain proper relationship with 360 degree tracer stylus it is necessary to guide the follower 133, Figure 3, in the correction mechanismv so thatit will take the position at the point of .tangeney 105, on the elliptical section of the cutter and/the dummy cylinder or form 124 resulting from therequired tilt at the point 101 of the contour 'on the workpiece and where contact between cutter and work should be established. This tangent line at 105 is parallel to the tangent line to the cylinder of cutter and to the. contour drawn through point 101.

The relationship between the angles t or t, and g and g, that is, the angles giving the position of the point of contact 105 of tracer and the cutter in the tilted position with respect to minor axis of ellipse, can be obtained by consideringthe geometry of the ellipse B, andthe circle C which is the circle of the tracer stylus and cutter.

From equation of ellipse:

Xe Ye F 7 tan m= tilted at a compound angle- 11.

14 Now X YET-f t 9? Hence:

tan n ==cot g1 cos inh. Since: a

=;9 -e cotgf= tan av Angle .m is also. the anglemade by theitangent to the circle C at point 101with. line AaA. Therefore t'=90- m d sixteen 07 Hence:

t =m nseque l an, zartanta s? I i This could also be written-interms-of z and g so that: n kt n t 5?",

This is mathematical relationship which exists between the position of a point such as 101 on "tracer stylus and the correspondingpoint, suchgas 105on the cutter when The correspondence is established on the condition that; the tangent at a point to the ellipse-ispar allel-tothetangent to the" base circle. The correspondence between the above equations and that given-for;thedouble-universal joint is self-evident.

In connection'wit-h the movement of the valves 194 and 204 as efiected bythe variable; positioning; of the member lfiti'to compensate-for the tilting movements of the'cutter it is necessary-to employ a suitableservofeedback mechanism coupled with the; compensator slides for eifectingan -opposite= or neutralizing positioning of the bushings 195 and 205, setting up a new and neutral or stationary-position ble the slides for each deflection of the valvementbers -by'the member-136.; The slidable mounting of the bushing 195and -205has been indicated in the hydraulic control diagram; Figure 16, and-the more complete structnral-details of theparts 194-195 have been shownin detail in Figure 3, it being'understood that the parts 204-205 correspond in structure.

The nature and operation of these feedback mechanisms should be readily apparent by reference to the general assembly-view,-Figure l, and the-moredetailedindication of the feedback structure as brought out i-n Figures 3, 6, and 16; As illustrated,thecompensating cross slide 55 is provided with arack 245 meshing with pinion 246 carried by shaft-247 Shaft 247 is provided'with asecond pinion 248 meshing with'rack- 249 and slide 250 reciprocable on the guide bracket 251. Pivoted to the slide'250 is the link 252on which is slidable the adjustable fulcrum block 253 pivoted at 257 on a slide guided by ways 254 on the ram 43. At its upper end the link-is slidable within ways in the shifter block 255 pivoted at 256 to theouter endof the bushing 205. By this construction any transverse movement of the slide 55 will transmit through the rocking link a selected linear movement to the bushing 205 to shut 01f the flow of actuating medium to cylinder 57 when the correct compensating movement of slide 55 has been eifected.

In ordinary practice the fulcrum point 257 will be sopositioned as indicated in Figure dthattherewill be none to one ratio between the slide effected movement of the lower end of the leverv andthe amount of movement imparted by the=upper end of the lever to theval ve. bushing; The fulcrum adjustmenhhowever, permits modification of this oneto one movement ratio sothat the actual slide movement may be either greater or less than the controlled valve 204, and bushing 2 05 movements to compensate for It will be understood that a corresponding feedback mechanism, including the shifting block 258, link or lever 259 and a corresponding drive for said link or lever are employed correspondingly to control the positioning of the bushing 195.

From the foregoing it will be noted that there has been provided in the present invention a completely automatic contouring machine particularly adapted for the production of air foil surfaces or the like in which a 360 degree tracer mechanism determines the contour or outline to be produced, and in which additional tracer mechanisms determine the individual angling adjustments of the cutter spindle to effect positioning of the cutter spindle at the proper resultant axially varied angle to insure the necessary relationship between the operative surface of the cutter and the work.

It will further be evident that there is provided in connection with such basic cutter angle position controlling mechanism, an efficient and accurate compensating or supplemental cutter positioning mechanism which is itself under control of the 360 degree tracer control mechanism and serves as a computing device through feedbacks from the angularly adjustable cutter supports for determination of necessary minor repositioning movements of the cutter to compensate for basic surface contact displacements resulting from the angular tilts or adjustments of the cutter.

Additionally, this measuring or computing device through hydromechanical elements automatically produces the necessary supplemental positioning of the cutter to maintain at all times a correct positional relation between the effective tangent plane of the work and operative surface of the cutter.

As has been pointed out, this mechanism is eifective,

not only in those instances where any variant in the cutter height with respect to the work may be disregarded, but also embodies a depth control and compensator mechanism effective to compute and automatically produce the necessary corrective positionings of the cutter when it is desired to maintain the effective edge of the cutter at a constant height irrespective of the variants which would be otherwise produced due to the tilting adjustments of a cutter about a point along the axis of the cutter as distinguished from about a point at the edge of the cutter.

What is claimed is:

l. A contour generating machine including a pair of main slides supported for relative transverse movements, a pair of auxiliary slides mounted for movement with one of said slides and for relatively transverse movements with respect to said slide and to each other, a cutter holder ,mounted on one of said auxiliary slides for tilting adjustment in two angularly related directions with respect to its supporting slide, a contouring tracer control mechanism for the pair of main slides to determine the contour following movement of the cutter holder, said mechanism including a tracer controlled rotary motor, a cutter position compensator including a form, means mounting the form for angular tilting adjustment in two angularly related directions in correspondence with the tilting of the cutter holder, motion transmitting connections between the cutter holder and the form for elfecting corresponding angular tilting of the holder and form, and means for shifting the auxiliary slides to compensate for bodily displacement of the cutter holder due to tilting, said means ineluding a form engaging follower, motors for moving the auxiliary slides and motor control valving for said motors connected to the follower for actuation thereby.

2. A contour generating machine including a pair of main slides supported for relative transverse movements, a pair of auxiliary slides mounted for movement with one of said slides and for relatively transverse movements with. respect to said slide and to each other, a cutter holder mounted on one of said auxiliary slides for tilting adjustment in twoangularly related directions with respect to lowing movement of the cutter holder, said mechanism including a tracer controlled rotary motor, a cutter position compensator including a form, means mounting the form for angular tilting adjustment in two angularly related directions in correspondence with the tilting of the cutter holder, motion transmitting connections between the cutter holder and the form for effecting corresponding angular tilting of the holder and form, means for shifting the auxiliary slides to compensate for bodily displacementof the cutter holder due to tilting, said means including a form engaging follower, motors for moving the auxiliary slides and motor control valving for said motors connected to the follower for actuation thereby, means mounting the follower for circumambulatory movement with respect to the axis of the form, and means for 'eifecting said circumambulatory movement.

3, A contour generating machine including a pair of main slides supported for relative transverse movements, a pair of auxiliary slides mounted for movement with one of said slides and for relatively transverse movements with respect to said slide and to each other, a cutter holder mounted on one of said auxiliary slides for tilting adjustment in two angularly related directions with respect to its supporting slide, a contouring tracer control mechanism for the pair of main slides to determine the contour following movement of the cutter holder, said mechanism including a tracer controlled rotary motor, a cutter position compensator including a form, means mounting the form for angular tilting adjustment in two angularly related directions in correspondence with the tilting of the cutter holder, motion transmitting connections between the cutter holder and the form for effecting corresponding angular tilting of the holder and form, means for shifting the auxiliary slides to compensate for bodily displacement of the cutter holder due to tilting, said means including a form engaging follower, motors for moving the auxiliary slides and motor control valving for said motors connected to the follower for actuation thereby, means mounting the follower for circumambulatory movement with respect to the axis of the form, and means for effecting said circumambulatory movement, said means including a drive transmission connected to the tracer controlled rotary motor for operation by said motor.

4. A contour generating machine including a pair of main slides supported for relative transversemovements,

a pair of auxiliary slides mounted for movement with one of said slides and for relatively transverse move- 'ments with respect to said slide, and to each other, a

adjustment in two angularly related directions in correspondence with the tilting of the cutter holder, motion transmitting connections between the cutter holder and the form foreffecting corresponding angular tilting of the holder and form, means for shifting the auxiliary slides to compensate for bodily displacement of the its supporting slide, a contouring tracer control mechanism for the pair of main slides to determine the contour folcutter holder due to tilting, said means including a form engaging follower, motors for moving the auxiliary slides, motor control valving for said motors connected to the follower for actuation thereby, means mounting the follower for. circumambulatory movement with respect the axis of the form, and means for elfecting said circumambulatory movement, said means including a drive transmission connected to the tracer controlled rotary notor for operation by said motor, said connection of the motor valving to the follower including a variably positionable valve controlling eccentric, and shifting emcee-es 17 means connecting the eccentric with the follower 'for movement of the eccentric in accordance with form determined positioning of the follower.

'5. A contour generating machine including a pair of main slides supported for relative transversemovements, a pair of auxiliary slides mounted for movement with one of said slides and for relatively transverse movements with respect to said slide, and to each other, a cutter holder mounted on one of saidauxiliary slides for tilting adjustment in two angularly related directions with respect to its supportingslide, a contouring tracer controlmechanism forthe pair of main slides to determine the contour following movement of the cutter holder, said mechanism including a tracer controlled rotary motor, a cutter position compensator including a form, means mounting the form for angular tilting adjustment in two angularly related directions in correspondence withthe tilting of thecutter holder, motion transmitting connections between the cutter holder and the form for effecting corresponding angular tilting of the holder and form, means for shifting the auxiliary slides to. compensate for bodily displacement of the cutter holder due to tilting, said means including a form engagingfollower, motors for moving the auxiliary slides, motor control valving for said motors connected to the follower for actuation thereby, means mounting the follower for circumambulatory movement with respectto the axis of the form, and means for effecting said circumambulatory movement, said means including a drive transmission connected to the tracer controlled rotary motor for operation by said motor, said connection of the motor valving to the follower including 'a variably positionable valve controlling eccentric, shifting means connecting the eccentric with the follower for movement of the eccentric in accordance with form determined positioning of the follower, and means independent of said connection between the eccentric and follower for effecting rotation of the eccentric.

6. A contour generating machine including a pair of main slides supported for relative transverse movements, a pair of auxiliary slides mounted for movement with one of said slides and'for relatively transverse movements with respect to said slide and to each other, a cutter holder mounted on one of said auxiliary slides for tilting adjustment in two angularly related directions with respect to its supporting slide, a contouring tracer control mechanism for the pair of main slides to determine the contour following movement of the cutter holder, said mechanism including a .tracer controlled rotary motor, a cutter position compensator including a form, means mounting the form for angular tilting adjustment in two angularly related directions in correspondence with the tilting of the cutter holder, motion transmitting connections between .thecutter holder andthe form. for effecting corresponding angular-tilting of, the holder and form, means for shifting the auxiliaryslides to compensate for bodily-displacement of the cutter holder due to tilting,-said means including a form engaging follower, motors. for moving the auxiliary slides and motor con trol valving for said motors connected to theTfollower for actuation'thereby aislide supporting theicutter holder for movement towardiand'from the=plane of contouring established by'the transverse movements of the fmain slides, a motor for moving said slide, a control valve for saidmotor, and means in the compensator tiltable with the formysaid means including a contact reacting on the valve variably to position the valve as said means are tilted.

7. Acontour generating machine including a pair of main slides supported jfor rlative transverse movements, a pair of auxiliary slides mounted for movementwith one of said slides'and for relatively transverse movements with respect to said slide and to eachother, a cutter holder mounted on one of "said-auxiliary slides for tilting adjustment in twoangularly related directions with respect to its supporting slide, a contouring tracer control mechanism for the pair of main slides to determine the contour following movement of the cutter holder, said mechanism including a tracer controlled rotary motor, a cutterposition compensator including a form, means mounting the form for angular tilting adjustment in two angularly related directions in correspondence with the tilting of the cutter holder, motion transmitting connections between the cutter holder and the form for effecting corresponding angular tilting of the holder and form, means for shifting the auxiliary slides to compensate for'bodily displacement of the cutter holder due to tilting, said means including a form engaging follower, motors for moving the auxiliary slides and motor control valving for said motors connected to the follower for actuation thereby, a slide supporting the cutter holder formovement toward and from the contouring plane established by transverse'movement of the main slides, a motor for moving said toward and from slide, a control valve for said motor, and means in the compensator tiltable with the form variably to position the valve as said means are tilted, said means including a rotarysupport, and an eccentric contact carried by the support, the valve control member having a disc portion for engagement by the contact, and means to effect arcuate movement of the contactabout the axis of its rotary support.

8. A contourgenerating machine including a pair of main slides supported for relative transverse movements, a pair of auxiliary slides mounted for movement with one of said slides and for relatively transverse movements with respect to said slide and to each other, a cutter holder mounted on one of said auxiliary slides for tilting adjustment in two angularly related directions with respect to its supporting slide, a contouring tracer control mechanism for the pair of main slides to determine the contour following movement of the cutter holder, said mechanism including a tracer controlled rotary motor, a cutter position compensator including a form, means mounting the form for angular-tilting adjustment in two angularly related directions in correspondence with the tilting of the cutter holder, motion transmitting connections between the cutter holder and the form for effecting corresponding angular tilting of the holder andform, means for shifting the auxiliary slides to compensate for bodily displacement of the cutter holder due to tilting, said means including a form engaging follower, motors for moving the auxiliary slides and motor control valving for said motors connected to the follower for actuation thereby, a slide supporting the cutter holder for movement toward and from the contouring plane'established by transverse movement of the main slides, a motor'for moving said toward, and from slide, a control valve for said motor, and means in the compensator tiltable with the form variably to posi-. tion the valve as said means are tilted, said means including a rotary support, and an eccentric contact carried by the support, the valve control member having a disc portion for engagement by the contact, and means to effect arcuate movement of the contactjabout the axis of its rotary support, said control valve including a pair, of relatively movable members, and a feedback connection between the toward and'from slide and one of said-valve members for eifecting relative movement of the valve members tolimit theslide movement.

9. A contour generating machine including a pair of main slides supported for relative transverse movements, a pair of auxiliary slides mounted for movement with one of said slides and for relatively transverse movements with respect to said slide and to each other, acutter holder mounted on one of said auxiliary slides for tilting adjustment in two angularly related directions with respect to its supporting slide, a contouring tracer control mechanism for the pair of main'slides to determine the contourffollowing movement. .of: the cutter; holder, said: mechanism 

